Police used computer experts to obtain confidential material, and are also believed to have approached Number 10's internet suppliers to gain access to government email records.....

The cash-for-honours investigation took another dramatic twist last night after it was alleged that detectives had uncovered a secret computer network at Downing Street from which potentially crucial emails had been deleted.

This is nonsense.

"Government email records" are highly protected. For example, all systems at Number 10 will be TEMPEST rated, preventing external eavesdropping. Plus the emails will be encrypted and their servers heavily protected against intrusion and attack.

If the cops "computer experts" successfully hacked this system, a) they committed a criminal offense, and b) the Security Services personnel responsible for the security of government communications should be fired.

And of course if the highly compromising emails were deleted, how come the cops know they were "potentially critical"? Anyway, this confirms it's a political hit:

Police are expected to report to the Crown Prosecution Service, which will decide if there should be any prosecution, next month. ITV News said that charges were unlikely because of the difficulties of proving any criminal intent.

Scotland Yard is close to submitting a report to the Crown Prosecution Service to ask it to consider whether there are grounds to extradite a Russian businessman in connection with the murder of Alexander Litvinenko, it was claimed last night...

Downing Street, fearing major damage to Anglo-Russian relations because of emerging evidence that there was a "state-related" Russian source of the polonium, is alleged by Yard insiders to have asked police to keep quiet about the inquiry.

Actually, the cops are bound in law to "keep quiet" about inquiries except in tightly controlled circumstances.